The present invention relates to means for interconverting thermal energy and electric power, and more especially to thermotunneling devices for cooling and power generation.
In U.S. Pat. No. 3,169,200 to Huffman, a multilayer converter is described which comprises two electrode, intermediate elements and oxide spacers disposed between each adjacent element. A thermal gradient is maintained across the device and opposite faces on each of the elements serve as emitter and collector. Electrons tunnel through each oxide barrier to a cooler collector, thereby generating a current flow through a load connected to the two electrodes.
One drawback is that the device must contain some 106 elements in order to provide reasonable efficiency, and this is difficult to manufacture.
A further drawback results from the losses due to thermal conduction: although the oxide spacers have a small contact coefficient with the emitter and collector elements, which minimizes thermal conduction, the number of elements required for the operation of the device means that thermal conduction is not insignificant.
There remains a need in the art therefore for a device having fewer elements, which is easier to fabricate, and in which losses due to thermal conduction are further reduced.